As society's population ages, and due to the significant advances in extending the average lifespan, there is a growing population of elderly people. The elderly are, on average, more likely to spend the daytime hours sitting, often for extended periods of time.
Furthermore, a significant portion of the aging elderly are ultimately institutionalized. Many residents of health care institutions, for a variety of health reasons, spend a large portion of their waking hours sitting.
Because of the increasing numbers of people who will engage in long-term and uninterrupted sitting activity, there is a need to provide chairs which comfortably accommodate these people. People who sit for long and uninterrupted periods of time are more comfortable if they are able to assume different seating positions during that period.
To accommodate long-term and uninterrupted seating by individuals, it is preferable to provide a chair whose back support may be reclined to substantially a horizontal position relative to the chair seat, allowing the user to effectively lie down without having to move from the chair. This is especially useful in the institutional health care environment in order to assist in providing proper nursing care without having to constantly physically move a patient from a chair to a bed and back again. In this respect, it is important to shift a resident's weight for comfort, to prevent skin breakdown from being seated in one position too long, and for certain specific medical treatments.
Further, chair seats may be tilted by providing a pivotable connection between the chair seat and a stationary chair frame. Chair seats which can be tilted increase user comfort and allow for changes in position to assist blood circulation when sitting for long periods, may assist in preventing injuries caused by poor posture.
Chairs can be designed to promote a significant amount of seat tilt and back recline by using hydraulically or electrically-powered mechanisms to cause movement of the chair frame members and, thereby, facilitating seat tilt and back recline. However, such chairs are prohibitively expensive, and this is a real concern to hospitals and institutions in an era of budgeting restraint.
Chairs that provide a significant amount of seat tilt by manual actuation are, in general, restricted in the amount of chair back recline that they can offer. This is due to physical limitations of current chair designs. In particular, when the chair set is in a titled position, movement of the back of the chair or other chair components will be restricted by either of:
any structure in the back of the chair; PA1 the mechanisms which permit back recliner seat tilt; or; PA1 the floor. PA1 a pair of substantially identical, parallel frame members, positioned in mutually-spaced apart relation with each other, each comprising an upper support member, a front member, a lower member, and a rear member; PA1 the front member fixedly coupled at a lower end thereof to the lower member; PA1 the upper support member pivotally coupled at one end thereof to an upper end of the front member; PA1 the rear member coupled at one end thereof to the upper support member and at an opposite end thereof pivotally coupled to the lower member; PA1 a back rest member disposed intermediate the frame members, having a point of pivotable coupling to corresponding upper support members of each of the frame members to allow the back rest member to be pivotally reclined from a substantially vertical position to an inclined position; PA1 a seat member disposed intermediate the upper support members, positioned forwardly of the back rest member; PA1 a pivotable joint within the upper support member to allow bending of the upper support member; and PA1 adjustable support means, adapted to cause the upper support member to resist a downward weight of a person sitting on the seat member. PA1 a lower leg support member disposed forwardly of the front member; PA1 a lower link arm member, pivotably coupled at one end to said back rest member at a position thereon downwardly disposed from said point of pivotable coupling to aid upper support members and pivotably coupled at another end to said lower leg support member; and PA1 an upper link arm member, pivotably coupled at one end to said back rest member at a position thereon intermediate said point of pivotable coupling of said back rest member to said upper support members and said point of pivotable coupling of said back rest member to said lower link arm member, and pivotably coupled at another end to said lower leg support member at a position thereon spaced apart from said point of pivotable coupling to said lower link member.
Accordingly, there exists a real need in the art for a manually operated reclinable chair which is manually adjustably positionable, capable of being fully reclined to substantially a horizontal position, and which can also achieve an appreciable degree of seat tilt.
It is also desirable for chairs having reclinable back feature to provide a means for supporting the lower legs and calves of a user of the chair in the horizontal position when the chair back rest is reclined and the user is lying with his/her back and substantially horizontal.